Autoinjector with audible indication of completed delivery

ABSTRACT

The present invention relates to a device for automatic injection of a product into an injection site. The product is being carried by a container having a proximal open-end, a substantially closed distal end, carrying a needle to provide an outlet port for the product from the container and a piston provided in the container and distally movable with respect to the container. The movement of the piston causes the product to be expelled from the container. The device further comprises: 
     automatic injection means for causing the piston to move with respect to the container; 
     a housing receiving the automatic injection means; 
     controlling means cooperating with the automatic injection means to produce an audible indicator when the piston is near the distal end of the container and the product is substantially completely expelled from the container thereby informing a user that injection of the product is completed; 
     The present invention is characterized in that the controlling means comprise at least an intermediate part coupled to the automatic injection means and at least a flexible part coupled to the housing, the intermediate part cooperating with the flexible part to produce the audible indicator.

The present invention relates to a device for automatic injection of aproduct ensuring the user that the product has been substantiallycompletely injected.

In the present application, the distal end of a component or of a deviceis to be understood as meaning the end furthest from the user's handduring proper use and the proximal end is to be understood as meaningthe end closest to the user's hand during proper use. Likewise, in thepresent application, “the distal direction” is intended for defining thedirection of the injection, and the “proximal direction” for definingthe opposite direction to the direction of injection.

Some illnesses necessitate regular injections for drugs or products, forinstance on a daily basis. In order to simplify the treatment of suchillnesses, some devices for automatic injection have been developed toallow the patient to perform the injection on its own.

Of course, since the patient is usually neither a nurse nor an educatedperson in medical devices, such devices for automatic injection mustprove to be very simple to use and very safe. In particular, it isimportant to ensure that a controlled dose of a product is injected withsuch a device, that is to say a complete injection must be performed.Moreover, in some cases, the user may withdraw the device for automaticinjection before the injection is completed. It is therefore importantfor the user to be informed that the product has been substantiallycompletely injected and that he may withdraw the device from theinjection site.

It is known from the patent application WO 2007/132353 an automaticinjection device wherein a sound is emitted during or at the end of theinjection, thereby indicating the patient that the injection iscompleted when the sound ceases or when the sound is made, respectively.

The present invention proposes a device for automatic injection of aproduct into an injection site, said device producing an audibleindicator when the injection is completed.

The present invention relates to a device for automatic injection of aproduct into an injection site. The product is being carried by acontainer having a proximal open-end, a substantially closed distal end,carrying a needle to provide an outlet port for the product from thecontainer and a piston provided in the container and distally movablewith respect to the container. The movement of the piston causes theproduct to be expelled from the container. The device further comprises:

automatic injection means for causing the piston to move with respect tothe container;

a housing receiving the automatic injection means;

controlling means cooperating with the automatic injection means toproduce an audible indicator when the piston is near the distal end ofthe container and the product is substantially completely expelled fromthe container thereby informing a user that injection of the product iscompleted;

The present invention is characterized in that the controlling meanscomprise at least an intermediate part coupled to the automaticinjection means and at least a flexible part coupled to the housing, theintermediate part cooperating with the flexible part to produce theaudible indicator.

The device of the invention allows the user to be clearly informed ofthe end of injection.

In an embodiment of the present invention, said intermediate part isadapted to deflect said flexible part substantially at the end of theinjection, said automatic injection means cooperating with saidintermediate part to release said flexible part allowing said at least aflexible part to return to a non-deflected position thereby generating asound.

The device of the present invention may further comprise a clappingpart, said at least a flexible part bumping onto the clapping part whensaid at least a flexible part comes back to said non-deflected position.

In another embodiment, said automatic injection means comprise at leasttwo elastic means and the intermediate part is located between said atleast two elastic means.

In a further embodiment, said housing comprises an inner rim located onits inner wall near its proximal end, and said elastic means comprise adistal coil spring and a proximal coil spring serially mounted, whereina distal end of said distal coil spring is intended to lean directly orindirectly against the piston and a proximal end of said distal coilspring leans against a distal side of the intermediate part, and whereina distal end of said proximal spring coil leans against a proximal sideof the intermediate part and a proximal end of said proximal coil springleans against said inner rim.

In a still further embodiment, after said flexible part has returned toits non-deflected position, said intermediate part is prevented to movein the proximal direction by an abutment surface located on saidhousing. Thus said distal coil spring may remain partly loaded at theend of the injection, thereby causing said piston to be maintained incontact with said distal end of the container.

The device may further comprise a piston rod for pushing the pistondistally, said piston rod being provided with a flange at its distalend, the distal end of said distal coil spring leaning against saidflange of the piston rod.

In another embodiment of the present invention, said piston rod isreceived within said distal and proximal coil springs, and saidintermediate part comprises a ring mounted sliding around said pistonrod.

In another embodiment of the present invention, said distal and proximalcoil springs are similar. In another embodiment of the invention, saiddistal and proximal coil springs are different. In particular, saiddistal and proximal coil springs can have same or different spring rate.

In another embodiment of the present invention, the clapping part ispart of said proximal coil spring.

In another embodiment of the present invention, the intermediate part ismade of metal or plastic.

The device of the present invention will now be further described inreference to the following description and attached drawings in which:

FIG. 1 is schematic longitudinal cross section view of a device of theinvention, before use;

FIG. 2 is a schematic longitudinal cross section view of the device ofFIG. 1 during the injection but before the end of the injection;

FIG. 3 is a schematic longitudinal cross section view of the device ofFIG. 1 in a position where the intermediate part cooperate with the atleast a flexible part;

FIG. 4 is a schematic longitudinal cross section of the device of FIG. 1after the end of the injection.

Referring now to the drawings, the present invention will now bedescribed in detail. FIG. 1 shows a schematic longitudinal cross sectionof a device for automatic injection according to the present invention,as provided to the user before use, and which is referred to as device 1in the following description. The device 1 comprises a container 2having a proximal open-end 3, a substantially closed distal end 4 andcarries a product 5. A piston 6 is provided in the container 2 and isdistally movable with respect to said container 2. As it will appear inthe description below, the movement of the piston 6 in the distaldirection is intended to cause the product 5 to be expelled from thecontainer 2 through a needle 4 a provided at the distal end 4 of thecontainer 2. The device 1 comprises also a piston rod 7 provided with aflange 8 at its distal end to push distally said piston 6. The devicefurther comprises a housing 9 provided at its distal end with a flexiblepart, a flexible leg 10 on the example shown, and at its proximal endwith an inner rim 11 located on the inner wall.

The device 1 further comprises an intermediate part under the form of aring 12 mounted sliding around said piston rod 7, in the examplerepresented on Figures.

The device 1 further comprises elastic means, which, on the devicerepresented in FIG. 1, are two coil springs serially mounted, a distalcoil spring 13 and a proximal coil spring 14. In an embodiment notshown, the elastic means may comprise one or more additional coilsprings. In the represented device 1 of the FIG. 1, said piston rod 7 isreceived within said distal and proximal coil spring 13, 14, whereinsaid distal coil spring 13 has its proximal end leaning against thedistal side 15 of the ring 12 and its distal end leaning against theflange 8. Said proximal coil spring 14 has its proximal end leaning onsaid inner rim 11, and has its distal end leaning on a proximal side 16of the ring 12. Before use, the distal and proximal coil springs 13, 14are loaded. As it will appear later in the description, the proximal anddistal coil springs 13, 14 act as automatic injection means and the userinitiate the injection by freeing said proximal and distal coil springs13, 14 with the help of triggering means not shown on figures. Thedistal and proximal coil spring 13, 14 can be the same or different, inparticular, they can have the same or different spring rates.

The device may further comprise an outer sleeve, not shown on figures,receiving the container 2 and the housing 9, and coupling said container2 and said housing 9.

The FIG. 2 shows a schematic longitudinal cross section view of device 1in use, after said proximal and distal coil springs 13, 14 have beenfreed but before the substantial end of the injection. The distal andproximal coil springs 13, 14 have started to expand, thereby pushing onthe piston rod 7 in the distal direction. Thus said piston rod 7 havecome into contact with the piston 6 and, subsequently causes the piston6 to move with respect to the container 2, expelling the product 5 fromthe container 2 and realizing the injection. The ring 12, coupled withthe distal and proximal coil springs 13, 14, moves in the distaldirection while said distal and proximal coil springs 13, 14 areexpanding.

The FIG. 3 shows a schematic longitudinal cross section view of thedevice 1 in use, close to the end of the injection wherein the ring 12cooperates with said flexible leg 10. Said flexible leg 10 is deflectedoutwards by the ring 12 moving in the distal direction, pushed by theproximal coil spring 14. The flexible leg 10 is maintained in itsdeflected position as long as the ring 12 puts a strain on said flexibleleg 10.

On FIG. 4 is shown the device 1 at the end of the injection. The piston6 is into contact with the distal end 4 of the container 2 and theproduct 5 has been substantially completely expelled. The ring 12 islocated outside the housing 9 and said flexible leg 10 is in thenon-deflected position. Substantially at the end of the injection, whilethe ring 12 is still moving in the distal direction, the proximal side16 of said ring 12 comes at the level of the distal end of said flexibleleg 10 and, once the ring 12 moves forward said strain is released,causing said flexible leg 10 to come back in its non-deflected position.While returning to said non-deflected position, said flexible leg 10bumps onto a clapping part 17 thereby producing a sound. On the exampleshown, the clapping part 17 is a part of said distal coil spring 13. Theaudible indicator or sound thus produced informs the user the injectionis completed and that the product 5 has been substantially completelyexpelled from the container 2. In another embodiment not represented,the clapping part is an additional piece, separated or not from saiddistal coil spring; this additional piece may be made of plastic. As itappears from the figures, the ring 12 and the flexible leg 10 act ascontrolling means cooperating with the automatic injection means, ie thecoil springs (13, 14) to produce an audible indicator when said piston(6) is near said distal end (4) of the container (2) and the product (5)is substantially completely expelled from the container (2) therebyinforming a user that injection of the product (5) is completed.

In the position shown on FIG. 4, the ring 12 is prevented to move backin the proximal direction by an abutment surface 18 located on thehousing 9 and corresponding, on the example shown, to the distal end ofthe flexible leg 10. This abutment surface 18 maintains the ring 12outside the housing 9 and said distal coil spring 13 partly loaded,ensuring that the piston 6 remains in its final position against thedistal end 4 of said container 2. Once the injection is completed, theuser removes the device 1 from the injection site.

The ring 12 can be made of different thickness, as long as it is adaptedto come in contact with said abutment surface 18, substantially at theend of the injection but not before. In particular, in a embodiment notshown of the present invention, the ring can have a thickness so that itdeflects said at least a flexible leg 10 all along the injection, ormost of the time of the injection, and releases said strain on said atleast a flexible leg 10 substantially and only substantially at the endof the injection.

1. Device (1) for automatic injection of a product (5) into an injectionsite, the product (5) being carried by a container (2) having a proximalopen-end (3), a substantially closed distal end (4), carrying a needle(4 a) to provide an outlet port for the product from the container and apiston (6) provided in the container (2) and distally movable withrespect to the container (2), the movement of the piston (6) causing theproduct (2) to be expelled from the container (2), said device (1)further comprising: automatic injection means (13, 14) for causing thepiston (6) to move with respect to the container (2); a housing (9)receiving the automatic injection means; controlling means (10, 12)cooperating with the automatic injection means (13, 14) to produce anaudible indicator when said piston (6) is near said distal end (4) ofthe container (2) and the product (5) is substantially completelyexpelled from the container (2) thereby informing a user that injectionof the product (5) is completed; characterized in that said controllingmeans (10, 12) comprise at least an intermediate part (12) coupled tothe automatic injection means (13, 14) and at least a flexible part (10)coupled to the housing (9), said intermediate part (12) cooperating withthe flexible part (10) to produce said audible indicator.
 2. Device (1)for automatic injection according to claim 1, characterized in that saidintermediate part (12) is adapted to deflect said flexible part (10)substantially at the end of the injection, said automatic injectionmeans (13, 14) cooperating with said intermediate part (12) to releasesaid flexible part (10) allowing said at least a flexible part (10) toreturn to a non-deflected position thereby generating a sound.
 3. Device(1) for automatic injection according to claim 2, further comprising aclapping part (17), said at least a flexible part (10) bumping onto theclapping part (17) when said at least a flexible part (10) comes back tosaid non-deflected position.
 4. Device (1) for automatic injectionaccording to claim 1, characterized in that said automatic injectionmeans comprise at least two elastic means (13, 14) and in that theintermediate part (12) is located between said at least two elasticmeans (13, 14).
 5. Device (1) for automatic injection according to claim4, characterized in that said housing (9) comprises an inner rim (11)located on its inner wall near its proximal end, and in that saidelastic means comprise a distal coil spring (13) and a proximal coilspring (14) serially mounted, wherein a distal end of said distal coilspring (13) is intended to lean directly or indirectly against thepiston (6) and a proximal end of said distal coil spring (13) leansagainst a distal side (15) of the intermediate part (12), and wherein adistal end of said proximal spring coil (14) leans against a proximalside (16) of the intermediate part (12) and a proximal end of saidproximal coil spring (14) leans against said inner rim (11).
 6. Device(1) for automatic injection according to claim 5, characterized in thatafter said flexible part (10) has returned to its non-deflectedposition, said intermediate part (12) is prevented to move in theproximal direction by an abutment surface (18) located on said housing(9).
 7. Device (1) for automatic injection according to claim 5,characterized in that the device (1) further comprises a piston rod (7)for pushing the piston (6) distally, said piston rod (7) being providedwith a flange (8) at its distal end, and in that the distal end of saiddistal coil spring (13) leans against said flange (8) of the piston rod(7).
 8. Device (1) for automatic injection according to claim 7,characterized in that said piston rod (7) is received within said distaland proximal coil spring (13, 14), and in that said intermediate partcomprises a ring (12) mounted sliding around said piston rod (7). 9.Device (1) for automatic injection according to claim 5, characterizedin that said distal and proximal coil springs (13, 14) are similar. 10.Device (1) for automatic injection according to claim 5, characterizedin that said distal and proximal coil springs (13, 14) are different.11. Device (1) for automatic injection according to claim 5, furthercomprising a clapping part (17), said at least a flexible part (10)bumping onto the clapping part (17) when said at least a flexible part(10) comes back to said non-deflected position, and characterized inthat the clapping part (17) is part of said distal coil spring (13). 12.Device (1) for automatic injection according to claim 1, characterizedin that intermediate part (12) is made of metal or plastic.